Risk estimators are sometimes used in clinical medicine as we try to quantify a patient’s likelihood of having an event (heart attack, stroke for example) or dying of a particular disease. We also use these formulas to guide therapy, such as blood thinners in certain types of heart arrhythmias.

The ASCVD (Atherosclerotic Cardiovascular Disease) Risk Calculator estimates an individual’s 10-year risk of heart disease or stroke. It uses information on age, gender, race, total cholesterol, HDL cholesterol, systolic blood pressure, blood pressure lowering medication use, diabetes status, and smoking status.

A similar mortality risk calculator for COVID-19 has been suggested, spanning a 0-40 range. It was generated from cohort study data performed in Canada. As you can see from the Figure below, risk begins to increase more steeply at a value of 25. The curve is essentially flat (near zero) for values below such. As with all risk estimates, this formula will likely change over time as we learn more.